Negative capacitance induced by redistribution of oxygen vacancies in the fatigued BiFeO3-based thin film

作者：Ke Qingqing; Lou Xiaojie; Yang Haibo; Kumar Amit; Zeng Kaiyang; Wang John^*

来源：Applied Physics Letters, 2012, 101(2): 022904.

DOI：10.1063/1.4733982

• Admittance spectroscopies
• Capacitance dispersion
• Fatigue process
• Negative capacitance
• Physical mechanism
• Polarization switching
• Switching cycles
• Transport kinetic
• Zero fields

The capacitance dispersion in La and Mg co-substituted BiFeO3 thin film has been studied at different stages of polarization switching. A negative capacitance (NC) behavior is observed in the sample that is fatigued above 10(9) switching cycles. The origin of the NC is investigated through analyzing relaxation processes and charge transport kinetics by admittance spectroscopy. An activation energy of similar to 0.6 eV and a zero field mobility mu(0) = 5.33 +/- 0.02 x 10(-13) m(2)/Vs are thus obtained. A physical mechanism is proposed to explain this behavior. It involves a redistribution of oxygen vacancies, which are trapped at the film/electrode interface during the fatigue process.

• 出版日期2012-7-9
• 单位西安交通大学